In a computer system having color graphics, it is desirable to display color data on many types of devices such as computer display screens and printers. However, due to the inherent displaying and color range differences between display devices, color data that represents a certain color in one device, does not match the same color in another. In order to ensure color matching between devices, it is necessary to translate color data when transmitting it between each device. There are several methods in which this is presently done and, in general, most methods includes generating a three-dimensional color look-up table (LUT). The color LUT functions to translate color data corresponding to a first display device (referred to as the source device) to color data corresponding to a second device (referred to as the destination device). The LUT stores color values corresponding to the destination device and functions such that when it is indexed, it provides the destination device with translated color data.
Presently, there are two common methods used to generate a color LUT. The first method relates to translating color data between a printer (destination device) and a display (source device). This method involves printing out a large number of color swatches from the printer. Often times, as many as 1500color swatches are printed. The colors are measured and then mapped to a corresponding color in the, source device's range of colors (also referred to as the device's color gamut) to generate the color LUT.
Since this process tends to be very time consuming another method developed involves printing and measuring fewer color swatches. This method utilizes algorithms to characterize the destination device. In this method, a reduced number of color swatches are taken and measured to obtain some initial color values for the LUT. These values are inserted into the mathematical algorithm representing the destination device to generate the remainder of the color values in the LUT.
The problem with both of these methods is that the LUT is rarely exactly right the first time it is created. Instead, it is typically necessary to adjust the color LUT to make it visually acceptable. This process generally involves changing values within the color LUT in some manner and then printing out more swatches of color on the printer to compare them with the display color. Often times this procedure involves many days of reiterative fine tuning steps.
The present invention is a method and system for editing a color LUT that does not require repeatedly printing out and measuring colors on the destination display device. Instead, the present invention provides the user a perceptually intuitive real-time method and system to edit color LUTs.